1. Field of the Invention
The invention relates to warning devices and refers more specifically to a device for warning a vehicle driver of low pressure in a tire. The device of the invention is particularly suited for use on large trucks having dual wheels in which the pressure in one tire on a single wheel may lose pressure while the other remains inflated so that it is difficult to recognize that the one tire is underinflated until the tire has been damaged and/or the other tire is also underflated.
2. Description of the Prior Art
In the past, tire pressure warning devices have been provided which monitor the pressure in a plurality of tires and provide an indication for the driver in response to predetermined pressures. Such prior art devices, however, such as exemplified, for example, in U.S. Pat. Nos. 3,527,189 and 3,756,190, have had mechanically actuated indicating devices and/or devices which have been complicated and therefore subject to malfunction.
Wherein devices of the past have been mechanical, they often have not provided sufficient warning to get the attention of the vehicle driver in time to prevent damage to an underinflated tire, or have been inflexible and therefore dangerous wherein they extend beyond the normal width of the vehicle to which they are secured.
The sophisticated electrical systems for warning of low tire inflation which have been provided in the past connected to buzzers and/or indicator devices in the cabs of the vehicles on which they are installed are subject to malfunction as indicated above. Further, such devices are economically unfeasible in many instances.